Resource depletion occurs when the raw materials available in a given geographic region are used up. Any resource of which there is a limited supply or that regenerates its supply over time at a limited rate can become depleted. Deforestation, mining, and oil consumption all consume resources that are commonly used in manufacturing and for other industrial concerns. Other activities, such as overfishing and over-farming, can also lead to the depletion of available resources. In some cases, resource depletion is not intentional and contributes nothing to any industrial or commercial concern — it is instead caused by unintentional contamination of a resource, such as through pollution.
There are many different underlying human causes of resource depletion, most of them linked to excessive consumption of commercial products and food in many parts of the world. Fossil fuels, for instance, are burned to produce energy for a vast number of different personal, commercial, and industrial concerns and are, accordingly, being rapidly depleted. The production of farmland also consumes many resources. Most farmland exists to support the meat industry, particularly in the United States. Space for farmland is often produced by clear cutting forests, which are important natural resources.
Natural resources are grouped into two primary categories: renewable resources and nonrenewable resources. Renewable resources are those that, over time, are naturally regenerated, such as animals used for food, forests, wind energy, and solar energy. Despite the fact that these are renewable, special care must still be taken to avoid depleting resources. If overfishing significantly reduces a fish population, for instance, it may not be able to reproduce sufficiently to repopulate and may, therefore, become extinct. Nonrenewable resources, on the other hand, are those which simply cannot be regenerated — metal ores, for instance, once taken from the Earth, do not regenerate.
Resource depletion is commonly studied in the field of economics because the availability of raw materials can have a significant impact on the global economy. The production of many different commonly-used items, particularly some electronics that depend on relatively rare materials, depends on a constant supply of materials that exist only in limited quantities. Resource depletion can have dire implications on the price and availability of such products.
Environmentalists are also very concerned with resource depletion, though generally for different reasons. Resource depletion can severely damage ecosystems, the environment, the atmosphere, and many other important aspects of the Earth. Individuals with environmental concerns, therefore, are generally more concerned with maintaining the overall health of the environment than with finding new sources of resources.